Just a few weeks after details emerged of millions of bottles of cheap Spanish wine being sold as French rosé, another high-profile case of counterfeit wine has been reported in Spain.

As revealed by Wine Spectator, Spain’s Civil Guard recently uncovered a counterfeiting ring that had been operating for four years. So far, four people have been arrested in connection to the ring, with four more currently under investigation.

Based in a restaurant called Don Álex Multibart, in the Galician town of A Coruña, the suspects are accused of producing fakes bottles of premium, collectible wines, including Dominio de Pingus and Bodegas Vega Sicilia. The restaurant’s owner is one of the four suspects to be arrested.

During the investigation, the Civil Guard discovered roughly 1,800 fake labels of the high-end wines, along with equipment for falsifying labels, and a machine that enabled the counterfeiters to print on corks.

Speaking to Wine Spectator, Civil Guard Lieutenant Abel Marín said, “The route of the fake wine bottles has been traced, from falsification to distribution.” According to Marín, the process involved purchasing cheap wine and lesser cuvées from the high-end wineries, before relabelling it as the wineries’ premium offerings, and selling bottles for more than ten times their worth.

The counterfeit wines were sold to private clients, as well as hotels and restaurants, and Marín believes the scheme brought in profits of roughly $1.7 million for the group. Authorities are now confident that no counterfeits remain on the market.